What is ICD-10 code C81.22?

C81.22 is the ICD-10-CM diagnosis code for Mixed cellularity Hodgkin lymphoma, intrathoracic lymph nodes. A type of Hodgkin lymphoma with mixed cellularity affecting lymph nodes in the chest area. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C81.22 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C81.22 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. C81.22 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. C81.22 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does C81.22 map to under V28?

C81.22 maps to CMS-HCC V28 21 (Lymphoma and Other Cancers). The category number and label come from the CMS-HCC V28 model file for payment year 2026.

What does C81.22 pay in RAF?

C81.22 carries a community, non-dual, aged (CNA) RAF weight of 0.671 under CMS-HCC V28 for payment year 2026. The weight comes from the CMS V28 relative-factor file, not a hand-typed table.

What is the V28 vs V24 difference for C81.22?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For C81.22, V28 maps to Lymphoma and Other Cancers at RAF 0.671 while V24 mapped to Lymphoma and Other Cancers at RAF 0.675. Both models can still appear in legacy data and in payer-specific lookback periods.

2026 ICD-10-CM C81.22: Mixed cellularity

C81.22 maps to CMS-HCC V28 21 (RAF 0.671). Documentation must support MEAT. MEAT criteria · RAF calculator · HCC Buddy coding tools

ICD-10-CM Code View

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Code lookupC81.22Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96)

C81.22

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Mixed cellularity Hodgkin lymphoma, intrathoracic lymph nodes

A type of Hodgkin lymphoma with mixed cellularity affecting lymph nodes in the chest area.

Buddy Insight

Mixed cellularity Hodgkin lymphoma of intrathoracic lymph nodes represents mediastinal or other chest lymph node involvement by this subtype.

CMS-HCC V28

Mapped

HCC 21

Lymphoma and Other Cancers

RAF 0.671

CMS-HCC V24

Mapped

HCC 10

Lymphoma and Other Cancers

RAF 0.675

ACA/HHS

Mapped

HCC 12

HHS-HCC 12

Varies by metal level

ESRD/PACE

Mapped

HCC 10

Lymphoma and Other Cancers

RAF 0.111

RXHCC

Mapped

HCC 21

Hodgkin Lymphoma and Other Ca...

RAF 0.410

Code Book Path

Official

C81Hodgkin lymphoma

C81.2Mixed cellularity Hodgkin lymphoma

C81.22Mixed cellularity Hodgkin lymphoma, intrathoracic lymph nodes

Inclusion Terms

Official

Mixed cellularity classical Hodgkin lymphoma

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C81.22 in this effective period.

Related Child Codes

Official

C81.20Mixed cellularity Hodgkin lymphoma, unspecified site

C81.21Mixed cellularity Hodgkin lymphoma, lymph nodes of head, face, and neck

C81.23Mixed cellularity Hodgkin lymphoma, intra-abdominal lymph nodes

C81.24Mixed cellularity Hodgkin lymphoma, lymph nodes of axilla and upper limb

C81.25Mixed cellularity Hodgkin lymphoma, lymph nodes of inguinal region and lower limb

Includes

Official

ICD-10-CM does not list Includes notes for C81.22 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for C81.22 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C81.22 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C81.22 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C81.22 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Pathology confirming mixed cellularity subtype (not nodular sclerosis)

Chest imaging documenting intrathoracic lymph node involvement

Assessment for mediastinal bulk

B-symptoms assessment

MEAT Support

HCC Buddy guidance

Pathology confirming mixed cellularity subtype (not nodular sclerosis)

Chest imaging documenting intrathoracic lymph node involvement

Assessment for mediastinal bulk

B-symptoms assessment

Audit Caution

HCC Buddy guidance

Assuming intrathoracic Hodgkin lymphoma is nodular sclerosis without pathologic confirmation

Using unspecified site when chest imaging documents mediastinal lymphadenopathy

Confusing with primary mediastinal large B-cell lymphoma, which is a non-Hodgkin lymphoma

Not recognizing that mixed cellularity in the mediastinum is less common and warrants careful pathology review

Common Mistakes

HCC Buddy guidance

C81.12 — Nodular sclerosis, intrathoracic: Far more common at this location; pathology must confirm mixed cellularity

C81.20 — Mixed cellularity, unspecified site: Use C81.22 when intrathoracic involvement is documented

C85.22 — Mediastinal large B-cell lymphoma: Different lymphoma entity entirely

C81.02 — NLPHL, intrathoracic: Different subtype

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is C81.22 an HCC code?

Yes. C81.22 (Mixed cellularity Hodgkin lymphoma, intrathoracic lymph nodes) maps to Lymphoma and Other Cancers under the CMS-HCC V28 risk adjustment model (and Lymphoma and Other Cancers under V24), with a community non-dual aged RAF of 0.671. It is billable for payment year 2026.

Coder answer: C81.22 is billable and maps to V28 HCC 21, Lymphoma and Other Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C81.22
Description: Mixed cellularity Hodgkin lymphoma, intrathoracic lymph nodes
HCC (V28): HCC 21 — Lymphoma and Other Cancers
RAF: 0.671
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 21, Lymphoma and Other Cancers

0.671

V24HCC 10, Lymphoma and Other Cancers

0.675

ESRDHCC 10, Lymphoma and Other Cancers

0.111

RxHCCHCC 21, Hodgkin Lymphoma and Other Cancers

0.410

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work C81.22 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for C81.22

For C81.22 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed C81.22 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

C81.22 is the ICD-10-CM diagnosis code for mixed cellularity hodgkin lymphoma, intrathoracic lymph nodes. A type of Hodgkin lymphoma with mixed cellularity affecting lymph nodes in the chest area. C81.22 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lymphoid, hematopoietic and related tissue (c81-c96).

Under the CMS-HCC V28 risk adjustment model, C81.22 maps to Lymphoma and Other Cancers (HCC 21) with a community, non-dual, aged base RAF weight of 0.671. Under the older V24 model, C81.22 mapped to the same category but with a base RAF weight of 0.675, V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Verify the specific site of involvement is documented as intrathoracic (chest) lymph nodes. Because C81.22 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for C81.22 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify the specific site of involvement is documented as intrathoracic (chest) lymph nodes
•Confirm the histological type is mixed cellularity and not another Hodgkin lymphoma subtype

Clinical Significance

Mixed cellularity Hodgkin lymphoma of intrathoracic lymph nodes represents mediastinal or other chest lymph node involvement by this subtype. While intrathoracic involvement is the hallmark of nodular sclerosis Hodgkin lymphoma, mixed cellularity can also present in the mediastinum, though less commonly. Distinguishing between subtypes at this location requires pathologic confirmation and has implications for prognosis and EBV association.

Documentation Requirements

✓Pathology confirming mixed cellularity subtype (not nodular sclerosis)
✓Chest imaging documenting intrathoracic lymph node involvement
✓Assessment for mediastinal bulk
✓B-symptoms assessment
✓Complete staging workup
✓Treatment plan

Commonly Confused Codes

•C81.12: Nodular sclerosis, intrathoracic: Far more common at this location; pathology must confirm mixed cellularity
•C81.20: Mixed cellularity, unspecified site: Use C81.22 when intrathoracic involvement is documented
•C85.22: Mediastinal large B-cell lymphoma: Different lymphoma entity entirely
•C81.02: NLPHL, intrathoracic: Different subtype